Cracked plastic molding

[Saphirra]

I picked up a tank and stand I found.

The tank is 12.5"×36×25". 

I noticed that 2 of the corners of the plastic molding are cracked and it lifts right off the tank.  I can't tell if this is structural for this tank model or just for a lid.  It doesn't have a lid with it.  There is no plastic molding on the bottom.  The stand is metal.  The glass is significantly thicker than my other tanks.

Before I attemp filing this tank is it safe to put the tank on this stand without a solid flat surface?  I thought the glass needed something under it so it didn't crack.

Can the plastic portion be replaced?  If so, where can I get it?  I would love to have a glass top for it as well.

[tanksalot360]

I’ve seen full 120g reef tanks with cracked frames like that not posing a problem (on a BOTToM corner). But...the tank was also placed on 1/2” pink insulated foam which helps disperse and even out the tank load. First, I would recommend checking out a tank building calculator online to check if the glass thickness and height negates the use of a centre brace on the top frame. The cracking may be the result of a slight bow in the glass when filled. If the math doesn’t work out, I might be tempted to using a little abs solvent and a clamp on the plastic frame for a small repair attempt. I know big als used to and may still have access to the frames separately. Otherwise, a few options....You could remove the top frame and reinforce the two ends with 3-4” wide glass braces and silicon (similar to eurobracing) OR I’ve seen 3” wide stainless steel bent at 90 degrees and siliconed on to reinforce the centre.
And finally you can place the tank on insulating foam board, plywood with yoga mat or any other kind of material that might give a bit and help self leveling the tank bottom. Even short carpet can work.

Hope that helps